PYCNCH HYTRIUM. 113 



S. globosum, Schroet. Where the attack is severe, this cau- 

 pearly swellings or incrustations ; it frequents plant- like /"/..///. 



Hnl / ii in, Arliilhn, >SV,//r////x, J///XH//.S. 



S. mercurialis, Fuck., is very common on Mercurialis perennis 

 though seldom injurious to it. One severe ca>r is thus de- 

 scribed by Schroeter : " In sprin- tin- stem of tin- plant wa- 

 covered by a thick uneven glassy crust, which in course of time 

 became raised into wing-like processes running down tin- -tern 

 and coated on both sides with white granules of the immature 

 parasite : the leaves wen- completely rolled together, crumpled, 

 and covered with glistening prominences as with line silver sand. 

 The plant in this condition developed poorly, scarcely flowered, 

 and soon died, so that by the end of September f<'W di-ea-ed 

 example^ eould be found." 



CLADOCHYTRIACEAE. 



The vegetative body is frequently a branched mycelium. It 

 lives intercellular a- a saprophyte, or intracellular as a para.-ite. 

 and forms intercalary or terminal swellings, in which zoo.-por- 

 angia or resting-spores are produced, then it disappears. Sexual 

 reproduction does not occur. The parasite lives in and torm- 

 swellings on aquatic plants, or land plants in moist situation-. 

 The genera f'/vy /////////.> and / '/t //>.< /,///"' contain species parasitic 

 on higher plants; together with the saprophuic r/^A/.^;.*/-///,;//,///,. 

 the.-e are regarded by Fi.-cher as sub-genera of C/n, /i>r/ti/ffit'//i. 

 and as such they are also here regarded. 



I' '/i/i ///// As has both xoosporangia and rest in--.-pores. 

 has only rest in- spores, Cladosporangium only x 



angia. 



Urophlyctis. 



The delieate mycelium is uidnanclied, or only sliglitl\ 

 1'iaiiehed, and li\'es endoj)hytic, boring through the \\all- of 

 the host-plant. Al the place win-re a hypha enters a host- 

 plant it forms a swelling or colleciing cell (saminel/ell ), which 



je||e]-;dly becomes d i 1 1 e 1 'ell I ia t ed into a larger cell rich ill colitelll 



ami an outer -mailer one with l'-w content.-, but with line 

 terminal bristl-- Kiom the collecting cells nc\\ h\ph.i. 



Iliale alld produce other rolled ilrj cells ill liejgl llioll 1'ilrj 



ho-! - ( -ells. The /oo-poiaiigia aiv -ituated oilt.-ide the ho-l-cell- 



II 



